OK, I downloaded and looked in the manual for it from here
http://download.vso-s...tXtoDVD_v4_manual.pdf
and according to that you should have a settings menu! (it's so helpful when manuals are wrong!)
Try looking on the tools menu for a settings or options and have a look round, there will be a place you can select the DVD drive it uses and I expect it set to the wrong one at the moment.
(I have no personal experience of this software BTW, as I said I downloaded the manual and had a quick look through it)